1. Field of the Invention
The present invention relates to an identification device and method. Particularly, the present invention is directed to an improved radio frequency identification tag that may be read by both optical and electromagnetic means for identifying objects.
2. Description of Related Art
A variety of identification devices are known in the art for identifying objects by using optical means or electromagnetic means. For example, bar codes have existed for many decades wherein an optically readable bar code is provided that may contain information in machine readable format. When such a bar code is optically scanned by a scanner, this information may be read.
Likewise, radio frequency identification (“RFID”) systems have also existed for quite some time and are widely used. In such devices, a resonant circuit is provided that may detect and transmit electromagnetic radiation containing identification information.
Electronic identification such as RFID systems typically comprise two devices which are configured to communicate with one another. Preferred configurations of the electronic identification systems are operable to provide such communications via a wireless medium. For example, such a system may include an interrogator and a remote transponder, such as a tag or card. Such systems are described, for example, in U.S. Pat. No. 6,356,764, which is incorporated by reference herein in its entirety.
Such communication systems may be used in various applications such as identification applications. The interrogator is configured to output a polling or interrogation signal which may comprise a radio frequency signal including a predefined interrogation code using which the interrogator may address remote transponders. The remote transponders of such a communication system are operable to transmit an identification signal responsive to receiving an appropriate polling or interrogation signal.
More specifically, the appropriate transponders are configured to recognize the predefined code. The transponders receiving the code may subsequently output a particular identification signal which is associated with the transmitting transponder. Following transmission of the polling signal, the interrogator is configured to receive the identification signals enabling detection of the presence of corresponding transponders.
Such communication systems are useable in identification applications such as inventory or other object monitoring. For example, a remote identification device may be attached to an object of interest. Responsive to receiving the appropriate polling signal, the identification device is equipped to output an identification signal. Generating the identification signal indicates the presence or location of the identification device and the article or object attached thereto.
Such conventional methods and systems generally have been considered satisfactory for their intended purpose. However, many applications are well suited for use with a combination of the bar code and RFID systems. For example, RFID tags on groups of objects, such as saleable goods, that are stored on pallets as the pallets are brought into and move through a warehouse or stocking department may be used to efficiently track inventory, while bar codes on each individual item may be used in the purchase of each object by a consumer.
Accordingly, there is a strong need for methods and systems that can efficiently utilize the bar code and RFID systems in conjunction with one another. Although solutions to this problem have been developed, such as by placing individual separately manufactured bar codes and RFID tags on such objects, this results in more expense and complication than using only one such identification system. Moreover, while a bar code can usually be printed, manufacture of RFID tags generally involves a separate manufacturing operation, and subsequent steps of applying the RFID tag to a substrate, and then eventually to the object that is to be tracked. Thus, there still remains a continued need in the art for a system that can efficiently utilize the bar code and RFID systems in conjunction with one another. The present invention provides a solution for these problems.